1. Field of the Invention
The present invention relates generally to printing objects that are liable to be stacked.
This is the case with compact discs, for example.
2. Description of the Prior Art
The present invention relates more particularly to the situation in which the printing machine used to print such objects includes a circular printing table with regularly spaced around its perimeter a plurality of object stations each adapted to receive an object to be printed and which rotates stepwise about a vertical axis to move the object stations in succession to a loading station, to a plurality of workstations each including printing means, and to an offloading station; a loading system at the loading station includes a presentation device adapted to move to the loading station at least one stack of objects and a transfer device which, operating between the presentation device and the printing table, has at least one pick-up unit by means of which it picks up an object from the stack on the presentation device and then puts this object down at one of the object stations of the printing table.
In practise there is usually one workstation for each colour to be printed and at the loading station the transfer device of the loading system picks up the objects to be printed from the presentation device one by one and puts them down on the printing table one by one.
The production throughput of the system is therefore determined by that of the loading system.
A general object to the present invention is a system enabling the production throughput to be doubled and which also has other advantages.